1. Field of the Invention
The present invention relates to a control system for controlling an air-conditioner on an electric vehicle, and more particularly to a control system for an air-conditioner on an electric vehicle which is propelled by a propulsive electric motor energized by a high-voltage battery.
2. Description of the Related Art
There has recently been proposed an electric vehicle that can be propelled by a propulsive electric motor energized by a motor inverter which is supplied with electric energy from a high-voltage battery of 240 V, for example.
An air-conditioner on such an electric vehicle includes a motor-driven compressor which can be actuated by an air-conditioner electric motor energized by an air-conditioner inverter. The air-conditioner inverter is supplied with electric energy from the high-voltage battery. The air-conditioner with the motor-driven compressor will also be referred to as a motor-driven air-conditioner.
Therefore, the high-voltage battery on the electric vehicle serves as an energy source for both propelling the electric vehicle and actuating the air-conditioner conditioner. Since the high-voltage battery has a high voltage, the electric vehicle is required to have some protection for the electric circuit connected to the high-voltage battery. It is also necessary to manage the consumption of electric energy by the propulsive electric motor and the air-conditioner electric motor because the high-voltage battery has a limited energy storage capacity.